Large-scale networks traditionally operated according to distributed routing protocols. More recently, software-defined networking protocols have evolved to allow for centralized control of network elements. Network elements transfer user data via a data plane network. Controllers in a software-defined network (SDN) can communicate network control information to network elements via a control plane network (CPN). A CPN using the same physical links as the data plane network can be referred to as an in-band CPN. A CPN using dedicated physical links separate from the data plane physical links can be referred to as an out-of-band CPN.